Mining machine cutter bit



Sept. l1, 1956 l J, F JOY MINING MACHINE CUTTER BIT Original Filed Oct. 28, 1948 United States Patent i MINING MACHINE CUTTER BIT Joseph F. Joy, Pittsburgh, Pa., assiguor to Joy Manufacturing Company, Pittsburgh, Pa., a corporation of Pennsylvania I Original application October 28, 1948, Serial No. 57,046. yzifitsltsl and this application April 12, 1954, Serial No.

7V Claims. (Cl. 262-33) This invention relates to cutter bits and more particularly to a mining machine cutter bit of the double-ended reversible type.

In cutter bits, and especially those used with the cutter chains of coal mining machines, .it has become common practice to place hard metal inserts in the cutting points to increase the resistance to Wear. Such hard metal inserts, which are usually composed of tungsten carbide, are usually secured, as by silver soldering or brazing, in recesses in the bit points and such cutting points, due to their brittleness, must be protected against sudden impact with relatively hard objects such as the chain blocks by which they are supported. Further, in cutter bits of the double-ended reversible type it has been found di'lcult to position the bit with respect to its supporting socket of a chain block so as to provide for the proper bit gauge in the reversed positions of the bit. The present invention contemplates improvements over known types of cutter bits in that the hard metal inserts are so supported and i positioned that they are substantially protected against damaging contact with the chain block or other hard object and means is provided for predetermining the bit gauge in either reversed positions of the bit on the chain block. u

An object of the present invention is to provide an irnproved cutter bit. Another object is to provide an irnproved mining machine cutter bit of the double-ended reversible type. A further object is to provide an irnproved cutter bit having a hard metal insert set in a novel manner in the cutting point so that the cutting point is substantially protected in either supported positions of the bit on the chain block. A still further object is to provide an improved cutter bit of the double-ended reversible type having improved means for predetermining the bit gauge. Other objects and advantages of the invention will, however, hereinafter more fully appear.

' This application is a division of my copending application, Serial No. 57,046, filed October 28, 1948.

In the accompanying drawing there are shown for purposes of illustration two forms which the invention may assume in practice.

In this drawing:

Fig. 1 is a side elevational view of a cutter bit constructed in accordance with the illustrative embodiment of the invention, with the bit shown in operative relation with respect to a conventional chain block.

Fig. 2 is a side elevational View, with a portion in section, illustrating a modified form of cutter bit supported in operative relation to its chain block.

In the embodiment shown in Fig. 1, a double-ended reversible cutter bit 1 is designed for use with a conventional support or chain block of a mining machine cutter chain, as shown in broken lines at 2. The cutter bit has a body formed with relatively inclined arm portions 3 and 4 disposed at an oblique angle and which, at their outer portions, support cutting points or tips 5. The cutting portions have hard metal inserts 6 desirably composed of tungsten carbide and Athese inserts are secured in recesses 2,762,617 Patented Sept. 11, 1956 ICC 7, as by silver soldering, brazing or otherwise,in a wellknown manner, as is fully disclosedsin my copending application, Serial No. 57,046, referred to above. u l

The cutting portions 3 and A4 of the cutter bit have p'aral`` lel front and rear plane surfaces 8 and 9 land projecting rearwardly from therear surfaces at the apex'of the angle, at the rear side of th bit, is an abutment or central projection 10 provided with opposed abutment surfaces 11, 11.' The hard metal cutting p'oints are set inwardly ,withv rel spect to the front faces 8, as shown at 12. The chain block 2 has a right-angle socket 13 for receiving the inactive cutting portion of the bit, and a usual set screw 14 engages the front surface 8 of the inactive portion to hold the rear surface 9 thereof against the rear socket wall. By setting the cutting points inwardly of the plane faces 8 of the bit body the inactive cutting point is protected from engagement with the bit support or block socket walls when the bit is secured in either of its reversed cutting positions on its support or block. The abutment 10 rests on the outer surface of the chain block and serves to limit inward movement of the inactive cutting portion of the bit in the socket and predetermines the projection of the active cutting portion from the block, thereby to provide a predetermined bit gauge.

In the modified embodiment shown iii Fig. 2 the improved cutting portions are shown embodied in a doubleended reversible cutter bit 15 which is designed for use with a conventional support or chain block shown in broken lines at 16 and fully disclosed in my copending application, Serial No. 57,047, iled October 28, 1948, now abandoned. The cutter bit has a body formed with relatively inclined arm portions 17 and 18 which, at their outer portions, support cutting points or tips. These arm portions are arranged at an obtuse angle and have plane parallel front and rear surfaces 19 and 20 which intersect along parallel lines, lying in a plane bisecting the bit body at the apex of the angle. These parallel surfaces terminate in cutting portions 21 which provide cuttingl points or hard metal tips 22 at the opposite extremities of the bit.l

The cutting portions are formed in the same manner as the cutting portions of the first embodiment and have the same self-sharpening characteristics and improved wearresisting qualities.

VThe inactive cutting portion of the bit is receivable in a longitudinally extending socket 23 formed in the chain block and is held in position therein by a usual set screw 24. By setting the cutting points inwardly' of the plane faces 19 of the bit body in the manner shown, the inactive cutting point is protected from engagement with the bit support or block socket walls when the bit is secured in` cutting position on its cutting support or block.`

As a result of this invention, an improved mining machine cutter bit of the double-ended reversible type is provided having an improved arrangement of the hard metal cutting points so that the inactive cutting point is substantially protected against contact with the bit support or block during use, thereby to reduce the possibility of damage to the cutting point. By the provision of the improved abutment at the back of the bit the inward projection of the inactive cutting point within the chain block socket may be limited and the projection of the active cutting point from the chain block may be predetermined, thereby to predetermine the bit gauge. Other advantages of the invention will be clearly apparent to those skilled in the art.

While there are in this application specifically described two forms which the invention may assume in practice, it will be understood that these forms of the same are shown for purposes of illustration and that the invention may be modified and embodied in various other forms without departing from its spirit or the scope of the appended claims.

What I claim as Vnew and desire to secure by Patent is:

1. A double-ended reversible cutter bit comprising a 20451. having relatively ialinsd; arm. Portions., saisi armpprtiprisl having planeJfront faces, the'inactivel arm portions' serving alternatelyv als` a support for the active arm portion andreceivable ina socket of a bit mountingin eitherl reversed position of the b it,V and hard metal in* sertssetvinto the opposite endsof said body-arm-portions andproviding front, cutting tips set` inwardly of said frontfazces. whereby an inwardly disposed front face when resting on a socket-wall with the bit in supported position serves to maintain the insert of the inactive cuttingtip outk of contact with the socket-Wall in either reversed'position of the bit.

n2.. Ajdoubleended reversible cutter bit having relatiyely inclinedgarm' portionsV terminating in cutting points at he opposite eittrernities,v of the bit, said arm portions ha '.Illg, relatively inclined frontcuttingfaces terminating irifcutting points set@ inwardly of said front faces, either oi; said arm portions.' adapted, for insertion in a socket of; ai, chain block andthe inactivearm portions serving alternately as aE support for the.. active arm portion with the." r:active cutting .point out of contact with the socketwalls, and a central projection at therear side of thev bitfnd' providing opposed abutment surfaces disposed atn right angles to said cutting faces respectively and adapted for alternate engagement with an outer surface Letters of archainblock thereby to predetermine the bit gaugeV in either reversed position of the bit, said projection lirnitingtheprojection of the, inactive cutting face within the, blockfsocket.

3l.V A double-ended reversible cutter bit having relatively inclined arm portions terminating in cuttingpoints atthe vopposite extremities of then bit, said arm portions having relatively inclined front cuttingA faces, either of said arm portions adapted for insertion in a socket of ac1iain block and theinactive arrnV portions serving alternately asY a, support for the active arnr portion, and

central projection'rat therear side of thebitvand providing opposed'abutment surfacesdilsposed at right angles toisaid cnltting.` faces` respectively yand adapted jfor .alternateengagementwith anrouter surface of; a chain block tionfof the inactive cutting-.point-and its insertwithinthefblockl-socket withthe'finsert ispacedV from the socket, wallsf. Y

4. double-endedreversiblej cutterv bit comprising,l a

eby Ato predetertnine the bit gauge in either reversedi `l on; of thebit, said cuttngpoints having hard metal ins rts set inwardly of said arm faces whereby whenV thebody having relatively inclined arm portions terminating in cutting points at the opposite extremities of the bit at the same side of the bitfbody, the inactive arm portions serving alternately as a support for the active arm portion and receivable in a socket of a bit mounting in either reversed positionof the Vbit, the active arm portion extendable forwardly and. outwardly with respect to the bit mounting, and hard metal inserts set into the opposite ends of said arm. portions and providing'front cuttingy tipsset inwardly of' the. front faces` of theA cutting points whereby the front face of the-,armA portion receivable in the. socket o f theY hity mounting; serves; tof

maintain the insert of thel inactivev cutting tip outV of contact with the bit mounting in either bit position.`

5. A cutter bit as set forth in clairn4 wherein a bit mounting for the bit is provided and said bit has a projection thereon at the side of the body opposite from said cutting, pointsv andn providing spaced, abutmentsurfaces alternately` engageable with, a.. surface of. saidbit mounting in the reversed positions of said bit foi-limiting the projectionY of the inactive.l bit point' withinthc socket of 'said mounting.

6. A cutterbit andbitmountingas set forth in claim 5 wherein said projection istdisposed at the rear sideof thebit at the juncture ofsaid relativelyv inclined armV portions andA said surfacesof said projection are alter: nately'engagible withl anexterior surface of saidbit mounting.v

7. A doubleended,reversible. cutter bit comprisingav body having relativelyy inclined arm portionssaid arm portions serving alternately asa support for the activeV arIrltPOrtion withthe inactive arm portion receivableY in a socket of a bit mounting in either, reversed position of ther bit, said'arm portions having planefront faces and terminating incutting tips' set inwardly of said front faces whereby an inwardly disposedrfront face,when y thebitis received linthe socket ofthebit mountingwiththe plane face-of the inactive arm portion restingv againstthewallof theV socket, serves to maintainthe-inactivey cuttingtip outof Contact with the socket-wall.

References Cited inthe tile, of Ythis patent Y UNITED STATESPATENTS 

